Heat exchanger



May 31, 1966 A. e. LARSON HEAT EXCHANGER n7 us 59 YNVENTOR.

ARTHUR G. L ARSON ATTORNEYS A. G. LARSON HEAT EXCHANGER May 31, 1966 3 Sheets-Sheet 2 Filed Feb. 1'7, 1964 FIG. 5 5

vi F 27 INVENTOR.

ARTHUR G. LARSON BY WW W 4 ATTORNEYS A. G. LARSON HEAT EXCHANGER May 31, 1966 5 Sheets-Sheet 5 Filed Feb. 17, 1964 R O N E W m ARTHUR G. LARSON BY M j/ AM? ATTORNEYS United States Patent 3,253,651 HEAT EXCHANGER Arthur G. Larson, Mound, Minn, assignor to McQuay, Inc., Minneapolis, Minn., a corporation of Minnesota Filed Feb. 17, 1964, Ser. No. 345,206 4 Claims. (Cl. 165-122) The herein disclosed invention relates to heat exchangers in which the heat exchange is produced by a fluid in motion.

In the use of a heat exchanger for cooling or heating fluids and particularly fluids for human consumption comprising a wall structure having a passageway extending therethrough and in which the fluid to be heated or cooled is on one side of the wall structure and the fluid producing heat exchange is on the other side of the wall structure, it frequently happens that leakage through the wall structure or through the joints between parts thereof will cause the heat exchange fluid to leak into the fluid being heated or cooled. Where the heat exchange fluid is a refrigerant and the fluid to be heated or cooled is for human consumption, such fluid would become contaminated and unfit for use and in certain cases death might be caused by such leakage.

In addition, due to the lack of adequate water supplies in many localities, water restrictions are imposed limiting the amount of water which can be used for heating or cooling purposes. In these areas heat exchangers are normally air cooled. However, air cooled condensers have disadvantages in that they are noisy, and in addition, they transfer substantial amounts of heat to the surrounding building. This latter disadvantage is of particular importance if the surrounding building is air conditioned since this additional heat creates an increased burden for the air conditioning system.

An object of the present invention is to provide a construction in which contamination of the fluid to be heated or cooled is prevented.

Another object of the present invention resides in providing a construction in which leakage between the two conduits conducting the two fluids cannot occur.

A still further object of the present invention resides in providing a construction utilizing a plurality of coils each formed from tubing having spaced runs extending substantially in the same direction and with the runs of each coil disposed adjacent to, but spaced from the runs of the other coil or coils and with spaced heat transfer members engaging the outer surfaces of the runs of the various coils.

An object of the present invention resides in constructing the heat transfer members as fins having apertures therethrough receiving the runs of said coils, with the fins transferring heat between the runs of the coils.

Another object of the present invention is to provide a heat exchanger construction which can be readily cooled by water, air, or a combination of air and water.

Other objects of the present invention reside in the novel construction and arrangement of parts and in the details of construction hereinafter illustrated and/or described.

In the drawings:

FIG. 1 is a side elevational view of a heat exchanger illustrating an embodiment of the invention, portions thereof broken away;

FIG. 2 is a plan view of the structure shown in FIG. 1, portions thereof broken away and shown in section;

FIG. 3 is an end view of the heat exchanger viewed from the end where the inlet and outlet connections are taken;

FIG. 4 is an elevational view of the other end of the heat exchanger;

FIG. 5 is a fragmentary detailed view in elevation illustrating the method of attaching the return bends between loops of the coils to the runs thereof, portions thereof broken away and shown in section;

FIG. 6 is a top plan of a heat exchanger capable of being liquid or air cooled, parts thereof being broken away and shown in section; and

FIG. 7 is an elevation view of the structure of FIG. 6.

For the purpose of illustrating the invention a simplified construction has been shown in which two coils 10 and 110 have been illustrated. The coil 10 consists of two sections 11 and 12 disposed adjacent one another. The section 11 consists of a number of loops or turns 13 each comprising two runs 14 and 15. The loops 13 are arranged one above the other in spaced relation and the runs 14 are staggered with reference to the runs 15. Return bends 16 connect the runs 14 and 15 of each loop or turn 13 together. The runs 14- and 15 of each of the loops 13 may be made integral with the return bends 16 connecting the same together. This may be accomplished by utilizing a piece of tubing of suflicient length and bending the same in the middle to form the return bends and the runs integral therewith.

The section 12 is similar to the section 11 and consists of a number of loops or turns 17 similar to the loops 13, each comprising two runs 18 and 19. The loops 17 are arranged one above the other in spaced relation and the runs 18 are staggered with reference to the runs 19. Return bends 21 connect the runs 18 and 19 of each loop 17 together. The runs 18 and 19 of each loop 17 may be made integral with the return bends 21 if desired as disclosed in connection with section 11. The location of the return bends 16 and 21 and the disposition of the loops and runs of the coil 10 are shown in FIG. 4.

The connection between the runs of the coil 10* at the other ends of the runs are shown in FIG. 3. Starting with the run 15 of the upper loop 13 of section 11 of coil 11), a return bend 22 connects this run with the run 14 of the following loop. Similarly each run 15 of each loop is connected to the run 14 of the adjacent loop. Thus, a continuous passageway is formed through the section 11. Section 12 is similarly constructed having return bends 23 which connect the runs 19 of each loop with the runs 18 of the following loops. Again a continuous passageway is formed through the section 12.

The upper run 14 of the upper loop 13 of section 11 has connected to it a conduit 24 which serves as an inlet to the coil 10. The lowermost run 15 of the section 11 has connected to it a conduit 25' which is also connected to the upper run 18 of the upper loop 17 of section 12. The lower run 19 of the lower loop 17 of section 12 is connected to a conduit 26 which serves as an outlet for the coil 14 Coil 111 is constructed in the same manner as coil 10 and the same reference numerals preceded by the digit 1 will be used to designate the corresponding parts. This coil is constructed in two sections 111 and 112 which have loops or turns 113 and 117. The loops 113 are formed with runs 114 and 115 and the loops 117 are formed with runs 118 and 119. Runs 114 and 115 of loops 113 and runs 118 and 119 of loop 117 are connected together by means of return bends 116 and 121.

The loops 113 are inserted between the loops 13 and the loops 117 are inserted between the loops 17. In

, this manner each of the runs of the coil lies adjacent a corresponding run of the coil 10 and is spaced therefrom. The section 111 has at its lower end a single run 131 which is disposed below the lowermost loop 113 of the section 111. The section 112 has a single run 132 disposed above the uppermost loop 117 of the said section. The runs 131 and 132 are connected together by means of a conduit 133 whereby the sections are connected together.

The other ends of the runs 115 of each loop is connected to the run 114 of the adjacent loop by means of return bends 122. Likewise, the runs 119 of the loops 117 are connected to the runs 118 of the adjoining loops by means of returns bends 123. The lowermost run 119 of the lowermost loop 117 is connected to a conduit 134 which forms an inlet for the coil 110. The uppermost run 118 of the uppermost loop 117 is connected to a conduit 135 which forms an outlet for the fluid to be heated or cooled.

The various runs of the coils and 110 are supported by means of a case 50 which comprises two end plates 51 and 52. These end plates have flanges 53 and 54 extending completely about the same. have suitable holes through which the various runs extend. The said runs also extend through a plurality of heat transfer members or fins 60 which make contact with the said runs and transfer heat from the runs of one coil to that of the other. The case 50 further comprises a sheet metal wra-p 154 having a top 55, a bottom 56, and sides 57 and 58. This wrap is attached to the These end plates flanges 53 and 54 by means of bolts 59 or other suitable I fasteners.

For the purpose of attaching the return bends 22, 23, 122 and 123 to the various runs of the coils the ends of the runs extend through the end plate 51 and are swaged to increase the bore of the same and to form pockets 27 in the same receiving the ends of the various return bends. The joints so formed are soldered together in the cus tomary manner. If desired, the pockets may be formed in the return bends.

While the two coils 10 and 110 have been shown as constructed from the same diameter tubing it can readily be comprehended that where a greater degree of heat transfer is required that one or the other of the coils may be made of greater diameter.

The invention may be used in connection with any type of apparatus where heat exchange is desired, the two coils being connected to the respective circuits conducting the fluid to be heated or cooled and the refrigerant.

The advantages of the invention are manifest. The heat exchanger can be constructed at less expense than certain other forms of heat exchange where coils are used for both the fluid to be heated or cooled and the heat exchange fluid. The exchanger can be constructed to provide any amount of heat exchange. With runs of the coils arranged as disclosed rapid transfer of heat from one coil to the other through the fins results. With the instant invention leakage of fluid from one coil to the other is prevented.

FIGS. 6 and 7 show a heat exchanger construction -wherein the cooling is accomplished by a combination of liquid and air cooling. Referring to FIGS. 6 and 7, there is shown a heat exchanger unit as previously described having a fan 140 mounted on one side thereof by means of mounting brackets 141 suitably attached to a plate 142 enclosing one side of the heat exchanger. Plate 142 has an aperture 143 therein, aperture 143 being substantially axially aligned with a shaft 144 of fan 140. A fan block 145 is mounted on shaft 144 and rotation of fan block 145 causes a movement of air through the heat exchanger and across the turns or runs of the exchanger coils. The direction of movement of the air is substantially parallel to the direction of the heat transfer members or fins 60, or in other words, transverse to the direction of the runs.

The combination cooling-heat exchanger construction shown in FIGS. 6 and 7 finds particular application in localities where there are restrictions on. the amount of water available for heat exchanger use. By using the combination heat exchanger, the amount of water necessary is greatly reduced and yet the exchanger exhibits high efliciency while at the same time being quieter and 4 producing less exhaust heat than straight air cooled exchangers.

Changes in the specific form of the invention, as herein described, may be made within the scope of What is claimed within departing from the spirit of the invention.

What is claimed is:

1. A heat exchanger comprising:

(a) a first coil formed from tubing having a plurality of spaced runs extending substantially in the same direction,

(b) means at the ends of the runs of the first coil connecting adjoining runs together to form a continuous passageway through the first coil,

(c) a second coil formed from tubing having a plu rality of spaced runs extending substantially in the same direction,

(d) means at the ends of the runs of the second coil connecting adjoining runs together to form a continuous passageway through said second coil,

(e) each of the runs of said second coil being adjacent to, and interposed between, runs of the first coil and extending in substantially the same direction as the runs of said first coil, said first and second coils adapted to simultaneously conduct fluids therethrough,

(f) said first and second coils being completely independent from one another so that a leak of one coil cannot contaminate a fluid flowing in the other coil, and

(g) a plurality of transversely extending heat transfer members disposed in spaced relation along the runs of both of said coils and contacting the outer surfaces of the runs of both of said coils to transfer heat between said coils.

2. A heat exchanger comprising:

(a) a first coil formed from tubing having a plurality of spaced runs extending substantially in the same direction,

(b) means at the ends of the runs of the first coil connecting adjoining runs together to form a continuous passageway through the first coil,

(c) a second coil formed from tubing having a plurality of spaced runs extending substantially in the same direction,

(d) means at the ends of the runs of the second coil connecting adjoining runs together to form a continuous passageway through said second coil,

(e) each of the runs of said second coil being adjacent to, and interposed between, runs of the first coil and extending in substantially the same direction as the runs of said first coil, said first and second coils adapted to simultaneously conduct fluids therethrough,

(f) a plane passing through adjacent runs of said first coil being inclined at an angle to the horizontal, and a plane passing through adjacent runs of the second coil being inclined at an angle substantially equal to the angle of inclination of said first coil,

(g) said first and second coils being completely independent from one another so that a leak of one coil cannot contaminate a fluid flowing in the other coil, and (h) a plurality of transversely extending heat transfer members disposed in spaced relation along the runs of both of said coils and contacting the outer surfaces of the runs of both of said coils to transfer heat between said coils.

3. A heat exchanger comprising:

(a) a first coil formed from tubing having a plurality of spaced runs extending substantially in the same direction, 7

(b) means at the ends of the runs of the first coil connecting adjoining runs together to form a continuous passageway through the first coil,

(c) a second coil formed from tubing having a plus (e) each of the runs of said second coil being adjacent to, and interposed between, runs of the first coil and extending in substantially the same direction as the runs of said first coil, said first and second coil-s adapted to simultaneously conduct fluids therethrough,

(f) said first and second coils being completely independent from one another so that a leak of one coil cannot contaminate a fluid flowing in the other coil,

(g) a plurality of transversely extending heat transfer members disposed in spaced relation along the runs of both of said coils and contacting the outer surfaces of the runs of both of said coils to transfer heat between said coils, and

(h) means for moving air across the runs of said coils transversely to the direction of said runs.

4. A heat exchanger comprising:

(a) a first coil formed from tubing having a plurality of spaced runs extending substantially in the same direction,

(b) means at the ends of the runs of the first coil connecting adjoining runs together to form a continuous passageway through the first coil,

(c) a second coil formed from tubing having a plurality of spaced runs extending substantially in the same direction,

(d) means at the ends of the runs of the second coil connecting adjoining runs together to form a continuous passageway through said second coil,

(e) each of the runs of said second coil being adjacent ROBERT A. OLEARY, Primary Examiner.

CHARLES SUKALO, FREDERICK L. MATTESON,

to, and interposed between, runs of the first coil and extending in substantially the same direction as the runs of said first coil, said first and second coils adapted to simultaneously conduct fluids therethrough,

(f) a plane passing through adjacent runs of said first coil being inclined at an angle to the horizontal, and a plane passing through adjacent runs of the second coil being inclined at an angle substantially equal to the angle of inclination of said first coil,

(g) said first and second coils being completely independent from one another so that a leak of one coil cannot contaminate a fluid flowing in the other coil,

(h) a pluralityof transversely extending heat transfer members disposed in spaced relation along the runs of both of said coils and contacting the outer surfaces of the runs of both of said coils to transfer heat between said coils, and

(i) means for moving air across the runs of said coils transversely to the direction of said runs.

References Cited by the Examiner UNITED STATES PATENTS 2,188,975 6/1940 Herz 165-14O 2,877,991 3/1959 Warrington 62-507 X FOREIGN PATENTS 537,907 7/ 1941 Great Britain.

JR., Examiners.

3 T. W. STREULE, Assistant Examiner. 

1. A HEAT EXCHANGER COMPRISING: (A) A FIRST COIL FORMED FROM TUBING HAVING A PLURALITY OF SPACED RUNS EXTENDING SUBSTANTIALLY IN THE SAME DIRECTION, (B) MEANS AT THE ENDS OF THE RUNS OF THE FIRST COIL CONNECTING ADJOINING RUNS TOGETHER TO FORM A CONTINUOUS PASSAGEWAY THROUGH THE FIRST COIL, (C) A SECOND COIL FORMED FROM TUBING HAVING A PLURALITY OF SPACED RUNS EXTENDING SUBSTANTIALLY IN THE SAME DIRECTION, (D) MEANS AT THE ENDS OF THE RUNS OF THE SECOND COIL CONNECTING ADJOINING RUNS TOGETHER TO FORM A CONTINUOUS PASSAGEWAY THROUGH SAID SECOND COIL, (E) EACH OF THE RUNS OF SAID SECOND COIL BEING ADJACENT TO, AND INTERPOSED BETWEEN, RUNS OF THE FIRST COIL AND EXTENDING IN SUBSTANTIALLY THE SAME DIRECTION AS THE RUNS OF SAID FIRST COIL, SAID FIRST AND SECOND COILS ADAPTED TO SIMULTANEOUSLY CONDUCT FLUIDS THERETHROUGH, (F) SAID FIRST AND SECOND COILS BEING COMPLETELY INDEPENDENT FROM ONE ANOTHER SO THAT A LEAK OF ONE COIL CANNOT CONTAMINATE A FLUID FLOWING IN THE OTHER COIL, AND (G) A PLURALITY OF TRANSVERSELY EXTENDING HEAT TRANSFER MEMBERS DISPOSED IN SPACED RELATION ALONG THE RUNS OF BOTH OF SAID COILS AND CONTACTING THE OUTER SURFACES OF THE RUNS OF BOTH OF SAID COILS TO TRANSFER HEAT BETWEEN SAID COILS. 